Enter Mudbox

A few years ago, Pixologic released a tool that changed
the way some people approached modeling: ZBrush. ZBrush
could be considered one of a kind because of its ability to
manipulate objects with a very high level of detail. That has now
changed with the arrival of XSI 6 and its Gigapolygon
architecture (if you went to SIGGRAPH last year you may remember
the model of the soldier, modeled to the very last detail) and
Mudbox, the newest ZBrush competitor (the other one being
ClayTools by SensAble. You can read about
ClayTools in my SIGGRAPH report here).

Mudbox was just released on December 2006, but it had been used
in production for a few years by New Zealand Studios such as WETA,
and it has evolved during the years. When I first used Mudbox it
felt very much like using ClayTools, save for the fact that
ClayTools uses the Phantom while Mudbox uses the mouse (or tablet,
if you have one). The program is extremely easy to use and
intuitive. One of the reasons that always kept me away from ZBrush
is that it just felt too confusing at first hand and I had to go
through many pages just to begin being productive. On the other
hand, Mudbox automatically became "second nature" (in
part because it operates very much like Maya in terms
camera navigation and tool operations).

While ZBrush and ClayTools claim to be able to handle models
with "unlimited level of detail", Mudbox describes itself
as a "high-resolution modeler". What it does is subdivide
the model as many times as you want, or need, depending on the kind
of detail you are after (I don't know if the same process is used
by ZBrush or ClayTools, though). The head pictured above has nearly
two million polygons, and on Skymatter's website you can see videos
of Mudbox operating on 14-million polygon models. You can subdivide
the model as many times as you want, and the program's core helps
you handle such high resolutions because it has a "polygon
cache" that stores data on the hard drive. However, the amount
of subdivide operations is limited to your CPU's power. I reached
the two million polygons after four subdivisions, but when I tried
a fifth subdivision on an Athlon 2700+, the program crashed. I then
tried the same on a Core 2 Duo laptop and it did it just fine.
Opposed to the CPU usage, the amount of memory used by the model
was surprisingly minimal: around 200 MB, which is less than what
Maya uses when you just start the program..

In Mudbox, you manage your objects using the Object
List. You have camera views, light sources, and materials,
just like Maya. This is one of the things I really liked about it,
because in ZBrush once you create an object (or a stroke) you can't
manipulate or modify it in any way after you have
"released" it. If you have many objects in your scene,
you can select any of them in the Object List and then make the
changes you want.

Being a sculpting program, Mudbox has a limited toolset
(basically a few pushing and pulling tools). Nevertheless, this is
not so bad since the tools can be modified with patterns, known as
stencils or stamps, to create a variety of effects. A stencil is
similar to a "brush," where the effect is replicated on
every stroke, while a stamp creates a projected texture that
deforms the objects using the direction normal to the camera view
(this means that the object's "normal angle" will affect
how the texture falls onto the object). The stencil works directly
on the surface's normal, while the stamp works as a "projected
image".

There is a tool that lets you draw curves, and you can use them
as guides for your strokes. If you create the curve and turn on the
"snap to curve" option, your brush will stick to that
curve (given a certain tolerance). You can then paint along that
guide curve.

Mudbox doesn't have a built-in renderer, so you can't view a
"smooth refined version" of your work. I have to admit
that at first it surprised me with the lack of a renderer, but the
camera view quality is good enough to let you know how the final
model wll look. After all, Mudbox is a sculpting tool, not a fully
integrated 3D program.

One of the things people will be most interested in will be how
well Mudbox plays with other software. In my case, I had to try
Mudbox and Maya, so I imported a model that I was working on, and
then I painted a lot of different effects on top of it. I would
then try to export those bulges and deformations as a displacement
map that I would bring back into Maya. The image below shows my
original model and the displaced model side-by-side.

The original model is a few hundred polygons, while the
displaced version has a little over 400 thousand. I took the
screenshot using wireframe view so you can see how dense the
subdivided model was. I then used Mudbox's "texture
baker" to create a displacement map. The documentation is
still somewhat poor, so I had to try different settings until I got
the results I wanted. The issue with the documentation will be
solved soon, as they are still working on it. However, there are no
plans for downloadable documentation, so you have to view it
online.

The next image shows the baker options. These are the settings
that I stuck with after a few trials.

I created a 32 bit displacment map (and no normal map), and then
I imported that into Maya. Luckily, there's a "settings"
drop-down list for the last settings (the ones I couldn't
understand, so I just selected the "Maya" preset) and
then moved on to create the map (there are no presets for Max, XSI
and such yet). As a final step, I applied that displacement map to
my model inside Maya, and after a couple of minutes I had my
render.

If you visit the Mudbox website, you can see the gallery where
there are some models created exclusively with Mudbox. On the
other hand, many people use these kinds of programs just as
finishing tools for their models. Either way, Mudbox will prove to
be a very useful tool in your work.

All supporting images
are copyright, and cannot be
copied, printed, or reproduced in any manner without written
permission.

Animation
Alley is a regular featured column with Renderosity Staff
Columnist Sergio Rosa
[nemirc]. Sergio discusses on computer graphics software,
animation techniques, and technology. He also hosts interviews with
professionals in the animation and cinematography fields.

January 15, 2007

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Article Comments

thanks for the review :) i am using Mudbox since beta 1 and must say it changed my artist life simple sculpt example http://www2.ravensoft.com/users/maristov/mud/mudude.jpg

Symbion7 ()
posted at 12:00AM Thu, 18 January 2007

Looks very intresting, and full of new stuff. Hope they will release a Trial Version soon, because i guess nobody spend 700 $ without a test run. Some Applications are great and got a lot of possibilities but the interface is not everybodys choice. So in my case with Z Brush or the Render Settings in Modo. I love the Modeller in Modo but i really hate the render setup. But Mudbox looks familiar.(What you can see on Screenshots) We will see ... :O)

Marque ()
posted at 12:00AM Thu, 18 January 2007

Great review and it looks interesting but at $299 for non comercial use I'm afraid it's not going into my toolbox. Thank you for the excellent info and pictures.

Jean-Luc_Ajrarn ()
posted at 12:00AM Thu, 18 January 2007

Thank you for this review, Sergio. :)

Peggy_Walters ()
posted at 12:00AM Thu, 18 January 2007

Looks interesting - good pricing too for the hobbist. Would like to see a displacement map in use with Vue 6 Infinite before making a final decision.

adh3d ()
posted at 12:00AM Thu, 18 January 2007

Great program and very expensive too.

nemirc ()
posted at 12:00AM Thu, 18 January 2007

Symbion7, a demo is already available. You can email Skymatter at support@skymatter.com and ask for it. P_W, if you get the demo, you can export that displacement and see the results for yourself :)